I have a Windows 10 computer and I have all aircraft flyable.If they are using a downloaded cockpit, they need to have a cockpit folder in the aircraft folder that contains the cockpit lod, all the .bmps, or .jpgs that the cockpit needs. In the main aircraft folder you need to have the correct cockpit.ini for that cockpit, for example: AlbatrosC3_COCKPIT.ini, and the aircraft.ini needs the proper cockpit call out line, for example: CockpitDataFile=AlbatrosC3_Cockpit.ini. If you are going to make an aircraft flyable using a stock Thirdwire cockpit, such as, say, the Fokker DVII cockpit for the DFW, you only need to put the proper cockpit call out line in the aircraft's ini file, ie: CockpitDataFile=FokkerD7_cockpit.ini. The aircraft will immediately appear in the flyable aircraft list if you do this, but the cockpit location might be off, so you might need to extract the FokkerD7_cockpit.ini and change the following lines to get it in the proper position:
Position=0.0,-1.0268,0.82
Offset=0.0,-0.1,0.0
These lines are from a different ini, I'm just using them as an example.
Are you using FE1, or FE2? I ask, because the modded file folder location is different between the two versions of the sim, and if you use the modded file folder location for the wrong sim, the sim you're using can't read the files. I am using FE2, not Gold, or FE1. These instructions work for both FE1 and FE2, but if the modded folders are in the wrong spot, the game can't read them. Hope this helps.